POST /messaging/v1/email/messages/{messageKey}

Sends a message to a single recipient via a send definition using a messageKey path parameter.

messageKeystringRequiredUnique identifier used to track message status. Can be automatically created when you create a message or provided as part of the request. Can be up to 100 characters, and there are no restricted characters. Each recipient in a request must have a unique messageKey. If you use a duplicate messageKey in the same send request, the message is rejected.
definitionKeystringRequiredUnique identifier of the definition.
recipientobjectRequiredObject that contains parameters and metadata for the recipient, such as send tracking and personalization attributes. Use this parameter to send to one recipient. Use either the recipient or recipients parameter, but not both.
recipient.contactKeystringRequiredUnique identifier for a subscriber in Marketing Cloud. Each request must include a contactKey. You can use an existing subscriber key or create one at send time by using the recipient’s email address.
recipient.tostringChannel address of the recipient. For email, it’s the recipient's email address.
recipient.attributesobjectInformation used to personalize the message for the recipient. Written as key pairs. The attributes match profile attributes, content attributes, or triggered send data extension attributes.
202  Request is accepted. Review example response.
 requestIdstringThe unique identifier of this request.
 errorcodestringError code for the exception
 messageKeystringUnique identifier to track message send status.
202 AcceptedRequest is accepted. Review example response.
400 Bad RequestInvalid request
401 UnauthorizedFailed to pass authorization
403 ForbiddenFailed to pass authorization.
500 Server ErrorInternal error